Quasi-optical power generation is currently an area of great interest that is being heavily researched and funded by the Department of Defense because of a lack of frequency sources in the millimeter and sub-millimeter wave frequency ranges. High power vacuum tube devices are available, but are not practical, especially in space communication applications, due to their large size and weight. Additionally, these devices require high voltages that are costly to operate. Therefore, the research efforts described above are focused at developing a high-power solid-state frequency source at millimeter and sub-millimeter wavelengths.
To achieve the desired power, prior art devices require spatial power combining and the use of individual oscillators that must be synchronized to oscillate in the same frequency and phase.
There are several known methods used to synchronize the oscillations. These include, for example, a Fabry-Perot resonator, use of an externally injected signal, coupling between radiating elements and transmission line connections between oscillators.
Current methods of synchronization have significant drawbacks. The output power of such techniques is limited by antenna efficiency. An outside power source is required in order to generate an externally injected signal which adds cost and complexity to the system. The upper frequency of such techniques is limited by the need to interconnect oscillators. Also, the above mentioned techniques and devices, and in particular the Fabry-Perot resonator, usually require a non-planar construction which adds complexity and cost to the manufacture of such devices.
There is a need for a high-power solid-state millimeter and sub-millimeter wave source that has an integrated planar structure, is self-synchronized, and has the potential for high output power.
It is an object of the present invention to provide a high-power solid-state millimeter and sub-millimeter wave source that has an integrated planar structure, is self-synchronized, and has the potential for high output power.
It is another object of the present invention to apply active devices in the alternate layers of a photonic bandgap crystal to provide a wave source with the potential for high power output.